Spatial light modulators (SLMs) are devices or arrays of multiple devices that can control or modulate an incident beam of light in a spatial pattern that corresponds to an electrical input to the devices. The incident light beam can be modulated in intensity, phase, polarization or direction. Some modulation can be accomplished through the use of Micro-Electromechanical System devices or MEMS that use electrical signals to move micromechanical structures to modulate light incident thereon.
One type of SLM is a ribbon light modulator, such as a Grating Light Valve™ (GLV®) commercially available from Silicon Light Machines Corporation of Sunnyvale, Calif. Referring to FIG. 1, the ribbon light modulator generally includes a number of ribbons 102 each having a light reflective surface supported over a reflective surface of a substrate 104. Each ribbon 102 may be deflectable toward the substrate 104 to form an addressable diffraction grating with adjustable diffraction strength. The ribbons 102 are electrostatically deflected towards the substrate 104 by integrated drive electronics formed in or on the surface of the substrate.
It is highly desirable to improve light modulators. In particular, there is a need to improve a light modulator having a substrate with a mirrored or highly reflective surface and to improve a method of manufacturing the same. It is desirable that light modulators be produced having uniform reflectivity between wafer lots. It is further desirable that any treatment or modification of surface layers on the substrate not interfere with or adversely effect any underlying circuits formed in an electronically active substrate.